It's a JunoSSE, see here
Juno Racing :: Innovators of beautifully engineered race winning race cars
A passenger seat can be fitted with no chassis mods, engine in our series (V de V UK) is the 2ltr Honda VTec coupled to a Hewland paddle shift transaxle. The V6 version uses a Jaguar engine but I'm sure you could fit just about any 4cyl or V6 of your own choosing, the car is sold as a rolling chassis, so take your pick and shove it in.
As for being streetable, SVA here in the UK would have a field day with it, but in the USA I'm not sure. Raise the ride height, fit some street tyres, it already has lights & indicators, might be possible. Couple of pics below, the red one is our test car, the blue one the race car.